Allow queues to define a viewGenerator instead of always using a BuildbotBuilderQueueView.
<rdar://problem/118257502>
Pull request: https://github.com/WebKit/WebKit/pull/20349
Committed 270667@main (6c526fb9c1f2): <https://commits.webkit.org/270667@main> Reviewed commits have been landed. Closing PR #20349 and removing active labels.